System of distribution.



C. LE G. FORTESCUE, SYSTEM or DISTRIBUTION. APPLICATION FILED OCT. C1915.

Patented Oct. 10, 1916.

INVENTbR [hr/a5 Ze 6 b esw ATTbRNEY UNITED STATES PATENT or-FicE.

CHARLES LE FOBTESCUE, OF PITTSBURGH, PENNSYLVANIA, ASSIGNOR TO WESTING- HOUSE ELECTBIC AND MANUFACTURING COMPANY, A CORPORATION OF PENNSYL- SYSTEM OF DISTRIBUTION.

Application filed October 7, 1915.

To all whom it may concern:

Be it known that I, CHARLES LE G. Fon- I TESCUE, a subject of the King of England,

and a resident of Pittsburgh, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Systems of Distribution, of which the following is a specification.

My invention relates to systems of electrical distribution, and particularly to systems of the kind in which a direct-current circuit, such as an electric railway circuit, 18 supplied with energy from an alternatingcurrent circuit through a vapor converter or another suitable current-rectifying device. The object of my invention.- is to provide a system of the above-indicated character iii which the supply of energy to the directcurrent circuit may be interrupted, upon the occurrence of an abnormal condition therein, without injury to the system or the ap-' paratus associated therewith. 1;-

Difliculty has usually been experienced in the interruption of the circuits of high-voltage direct-current electric railways, because such circuits are usually highly inductive and no means have ordinarily been provided for successfully dissipating. the energy stored in'the circuits, the discharge of which often damages the insulation.

I According to the present invention, this difliculty is avoided by placing the-auto matic circuit breakers in the alternatingcurrent circuit rather than in the directcurrent circuit, and by controlling them in accordance with the conditions existing in the direct-current circuit. v

Figure 1 of the accompanying drawing is a diagrammatic illustration of a system of distribution that, embodies my invention, and F 2 is a. curve representing the 781181 tions in current in the direct-current circuit of the systemwhenthc circuit breaker 1S opened,

- The present system comprises an alternat- Specification of Letters Patent.

Patented Oct. 10, 1916.

Serial No. 54,588.

nected to one conductor 9 of an electric railway, the other conductor 10 of which is connected to the cathode 11 of the vapor converter. The circuit 9.1O thus receives direct current through the transformer 3 and the converter 7.

Instead of providing a circuit breaker in the direct-current side of the system which is automatically tripped upon the occurrence of a ground or short circuit or other abnormal condition in the direct-current railway circuit, a circuit breaker 12 is employed between the alternating-current cir- 2 of the cuit 1 and the primary winding transformer 3, and this circuit breaker is arranged to be tripped upon the occurrence of an abnormal condition in the direct-current railway circuit .9-.10. The tripping mechanism of the circuit breaker comprises an actuating coil 13 that is connected. in

series with acondenser 14: between the conductors 9-10 of the railway circuit in substantially the manner 'set forth in my c0- .pending application, Serial No.- 't'0Q,011, filed through the coil 13, which thereupon becomes sufiiciently energized to trip the circuit breaker l2 and disconnect the transformer 3 from the alternating-current sup ply circuit 1. The energy stored inthe railway circuit 9 -l0 is'then' dissipated in; the resistance of the circ'uit', in the secondary winding4 of the transformerZ -and in 'the converter 7, without damaging-the insulation of the direct-current circuit or,the apparatus connected to it. 'This-will be best understood by a consideration-of Fig. 2 in which the straight portion 15 of the curve represents the normal current iii the circuit 9l0, the portion lfirepi-esents the increase in current following a short circuit, which increase continues for something less than a half cycle, and the part 17 represents the diminishing value of the current following the opening of the circuit breaker. The point 18 represents the maximum value to bility to damage caused by excessive volt ages.

It will he understood that other kinds and forms of ctirrent-rectifying devices may be employed in place of'the vapor converter 7, and that other means for tripping the cireuit breaker may be employed, as well as that many other modifications of the system may be made without departing from the spirit and scope of the invention.

I claim as in}- invention:

1. .\n electrical distribution system comprising an alternatinga-urrent circuit, a direcbcurrent circuit, rectifying means connected lherebctween. and means for interrupting the connection between the alternating-current circuit and the rectifying means only, in response to conditions of the directcurrent circuit.

2. An electrical distribution system comprising an alternatlug-current circuit, a direct-current circuit that receives power therefrom, and means for interrupting the allernating-current circuit only, in response to conditions in the direct-current circuit.

3. An electrical distribution system com prising an alternating-current circuit, a dlrtwt-currentcircuit, a vapor rectifier eonnected therchetween, a CllCUlb interrupter for the alternatingrcurrent circuit only, and electro-respons ve means operatively eonnectcd to the direct-current circuit for tripping the circuit interrupter under predetermined conditions in the direct-current circuit. i

4. An electrical distribution system com- 'prising' an alternating-current circuit, a.

direct-current circuit, a converter connected thcrcbetween, a circuit interrupter for the alternating-current circu t only, and means for tripping the circuit interrupter in reconditions n the sponse to predetermined direct-current circuit. 5'

5. In an electrical distribution system, thecombination with an altermiting-current circuit, a. direct-current circuit, a converter, and a transformer operatively connected between the converter and the alternatingcurrent circuit, of means for interrupting the alternating-current circuit side of the transformer under predetermined conditions in the direct-current circuit.

(5. In asystem of distribution, the combination with an alternating-current circuit, a direct-currentcircuit and a converter, and a transformer connected tlrercbetween, of a circuit interrupter for interrupting the alternating-current circuit side ot the transformer in response to conditions in the direct-current circuit.

7. In a system of distribution, the com bination with an alternating-current circuit, a direct-current circuit and a converter connected therebetween, of means for interrupting the alternating-ctn'rent circuit only, in response to conditions in the direct current circuit.

8. In a system of distribution, the combination with an alternating-current circuit, a dircct current circuit and a: converter and a transformer connected thcrebetween, of means fol-interrupting the connection between the alternating-current circuit and the transformer in response to predetermined conditions inthe direct-current circuit.

9. In a system of distribution, the combination with an alternating-current circuit,

a direct-current circuit and a converter and a transformer connected therebetween, of means for interrupting the connection between the alternating-current circuit and the transformer only, in response to pre determined conditions in the direct-current circuit.

10. In a syston of distribution, the combination with analternating-curnrnt circuit, 'a direct-current circuit and a converter connected therebetween, of means for discon- Meeting the converter only from the altermtting-current circuit when an overload traverses the direct-current circuit.

11. In a -s \'stem'of distribution, the 001m bination with an alternatiiig-current circuit, a direct-current circuitand a converter connected therebetween, of a circuitinterrupter connected between the converter and the 'alternating-current circuit and adapted to be tripped ivhen an overload traverses the direct-current circuit to thereby permit the energy of the direct-current circuit to be dissipated i'ntlie converter and in the directcurrent circuit. I

12. All electrical distribution system com prising an zilternaling-current circuit, a direct-currentcircuit that receives energy therefrom and means for so interrupting the alternating-current circuit when an overload traverses the direct-current circuit that the energy in the direct-current circuit will he di$ipated within itself. i

13. In a system of distribution, the combination with an alternating-current circuit and a direct-cm'rent circuit, of a transformer theprimary winding of .which is connected to the alternating-current circuit, a converter operatively connected to the direct-curreut circuit and the secondary winding of the Itl'tHlFfOl'lllQl', and means for -interrupting the primary winding of the transformer in response to predetermined conditions in the direct-current circuit.

14. In a systemof distribution, the combination with an alternatingcurrcnt circuit and a direct-current circuit, of a transformer the primary winding of which is connected to the alternating-current circuit, a converter operatively connected to the direct-current circuit and the secondary winding of the transformer, and means for interrupting the primary winding of the transformer in anticipation of predetermined conditions in the direct-current circuit.

In testimony whereof, I have hereunto subscribed my name this 29th day of Sept. 1915.

CHARLES LE G. FORTESCUE. 

